Assisted clutch

Abstract

A clutch comprises at least one friction disk and clutch plates adapted to clamp the friction disk(s). Elastic means act on at least one of the clutch plates and urge the clutch plates together to clamp the friction disk(s) and thereby engage the clutch. Clutch release control means comprising a pedal are adapted to unclamp the friction disk(s) and thereby release the clutch. Assistance means for the pedal cooperate with a combination comprising at least first and second mobile members each of which is adapted to move along a respective path at the same time as the other of the first and second mobile members, proportionately to movement of the movement transmission means interconnecting the first and second mobile members. The assistance means cooperate with the combination of mobile members, are disposed between the first and second mobile members and are operative on the control means according to a predetermined law as function of the simultaneous but non-identical movements of the first and second mobile members.

We claim: 
     
       1. Clutch comprising at least one friction disk, clutch plates adapted to clamp said at least one friction disk, elastic means acting on a least one of said clutch plates and adapted to urge said clutch plates together so as to clamp said at least one friction disk and thereby engage the clutch, clutch release control means comprising a pedal and adapted to unclamp said at least one friction disk and thereby release the clutch, assistance means for reinforcing the action of said pedal, a combination comprising at least first and second mobile members each of which is adapted to move along a respective path at the same time as the other of said first and second mobile members and proportionately to movement of said control means, and movement transmission means interconnecting said first and second mobile members, said assistance means cooperating with said combination of mobile members, being disposed between said first and second mobile members and being operative on said control means according to a predetermined law as a function of the simultaneous but non-identical movements of said first and second mobile members, said control means comprising at least one shaft, a fork fastened to said at least one shaft, a clutch release bearing on which said fork is operative and which is operative on said clutch plates so as to move them apart, a pivot pin for said pedal, a second shaft, and a toothed wheel on said second shaft being fastened to said second mobile member, said first mobile member being fastened to said at least one shaft and meshing with said toothed wheel, said assistance means comprising a spring having respective ends coupled to said first and second mobile members, the arrangement being such that with the clutch engaged said ends of said spring are substantially aligned with said at least one shaft, whereby said spring is charged when the clutch is engaged, a second spring with different characteristics to said first-mentioned spring and acting in opposition thereto, and contributing to aligning said ends of said first-mentioned spring with said at least one shaft when the clutch is engaged, and a toothed idler wheel on said at least one shaft meshing with said second mobile member, and said second spring having its ends respectively coupled to said first mobile member and said toothed idler wheel. 
     
     
       2. Clutch comprising at least one friction disk, clutch plates adapted to clamp said at least one of said clutch plates and adapted to urge said clutch plates together so as to clamp said at least one friction disk and thereby engage the clutch, clutch release control means comprising a pedal and adapted to unclamp said at least one friction disk and thereby release the clutch, assistance means for reinforcing the action of said pedal, a combination comprising at least first and second mobile members each of which is adapted to move along a respective path at the same time as the other of said first and second mobile members and proportionately to movement of said control means, and movement transmission means interconnecting said first and second mobile members, said assistance means cooperating with said combination of mobile members, being disposed between said first and second mobile members and being operative on said control means according to a predetermined law as a function of the simultaneous but non-identical movements of said first and second mobile members, stop means and a fixed frame, and wherein said first mobile member couples said combination of mobile members to said control means and said second mobile member is in two parts of which a first meshes with said first mobile member and the second is selectively coupled by said stop means to said first part and to said fixed frame, and said assistance means being disposed between said first mobile member and second part of said second mobile member. 
     
     
       3. Clutch according to claim 2, further comprising at least one auxiliary spring coupled to said fixed frame and at least one of said mobile members. 
     
     
       4. Clutch according to claim 3, wherein said at least one auxiliary spring is coupled on with clearance. 
     
     
       5. In a clutch comprising at least one friction disk, clutch plates on respective sides of the friction disk, elastic means acting on one of the clutch plates to clamp the friction disk between the plates, clutch release control means comprising a pedal, a first shaft connected to said pedal, and a release fork fastened to said first shaft and cooperable with a clutch release bearing for disengaging the friction disk from between clutch plates, the improvement comprising an assist mechanism for the disengagement of the clutch comprising a first mobile member defined by a large diameter sector gear fixed for rotation with said first shaft, a small diameter pinion meshing with said sector gear, said pinion being fixed for rotation with a second shaft, a second mobile member larger in diameter than said pinion and fixed for rotation with the second shaft, said first and second mobile members being mounted for movement along respective paths at the same time and proportionately with the movement of said clutch release control means, elastic assist means fixed at respective ends to said sector gear and said second mobile member, said elastic assist means applying a preload in the course of clutch disengagement to reduce pedal force, said sector gear and pinion amplifying the relative movement of the ends of said elastic assist means in response to a given rotation of said first shaft. 
     
     
       6. A clutch assist mechanism according to claim 5, wherein said second mobile member comprises a gear wheel. 
     
     
       7. A clutch assist mechanism according to claim 5, wherein said gear wheel meshes with an idler gear mounted on said first shaft. 
     
     
       8. A clutch assist mechanism according to claim 7, wherein an aligning spring opposing the action of said elastic assist means is fixed at one end to said sector gear and at the other end to said idler gear, said aligning spring urging the ends of said elastic assist means into alignment with the axis of said first shaft when the clutch is engaged. 
     
     
       9. A clutch assist mechanism according to claim 5, further comprising means linking said pedal to said shaft disposed on one side of the axis of said clutch, the assist mechanism being disposed on the other side of the axis of said clutch for balancing forces exerted on the fork. 
     
     
       10. A clutch assist mechanism according to claim 5, wherein one end of said elastic assist means is fixed to said sector gear and said sector gear has teeth having a center of curvature, said one end of said elastic assist means is proximate to the center of curvature of the sector gear teeth, said sector gear being fixed to said first shaft at a location being disposed between said sector gear teeth and said one end of said elastic assist means, the other end of said elastic assist means fixed to said second mobile member on the opposite side of said second shaft relative to said sector gear teeth. 
     
     
       11. A clutch assist mechanism according to claim 8, wherein one end of said elastic assist means is fixed to said sector gear and said sector gear has teeth having a center of curvature, said one end of said elastic assist means is proximate to the center of curvature of the sector gear teeth, said sector gear being fixed to said first shaft at a location being disposed between said sector gear teeth and said one end of said elastic assist means, the other end of said elastic assist means fixed to said second mobile member on the opposite side of said second shaft relative to said sector gear teeth.